I didn't. I don't think I ever did, in fact. There's a subtle change in the response that takes a little getting used to.

This is was irritated me. Raw input fixed the mouse drift issue for me. But it did cause a slight response or change to your overall sensitivity setting that takes a bit to get used too. but at least its consistent.

I did more research on this awhile back and found it was a Microsoft developer patch thats caused this.